feat(layouts): optional min/max lap time per track layout for practice

Each layout can carry its own lap window (set on creation, editable in
Settings, saved from Race Day during practice). Open/Free practice on
that layout uses it; races always keep the event's values.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

CHANGELOG.md

@@ -8,6 +8,17 @@ The application version is maintained in `package.json` and displayed in the adm
 
 No changes recorded yet.
 
+## 1.31.0 - 2026-10-07
+
+### Added
+
+- Min and max lap time per track layout, for practice. A rebuilt track is often shorter or longer, so each layout can have its own lap window:
+  - set when the layout is created (Settings, or the "New layout" button, which now also asks for a minimum lap time);
+  - edited later in the layout list under Settings;
+  - saved to the layout when edited from Race Day's lap window form while a practice session on a layout is in focus.
+
+  Empty means the event's value applies, as before. Open and Free practice on that layout use it, including a long-running Open Practice that is moved to a new layout. Qualifying, heats and finals always use the event's values, so a layout can never change the limits of a race.
+
 ## 1.30.0 - 2026-10-07
 
 ### Added